QuestionQUESTION: We were driving home from a wedding this afternoon when the battery light came on followed by the ABS light and the failure of the fuel gauge, tach and speedometer/odometer. The fuel gauge started to register again and then everything shut down and the engine died. All this happened in the space of about a 1/2 mile as I looked for a safe place to pull over. checked battery, starter, ignition, altinatior; replaced PCM but still not fixed. Now we just keep it running.
ANSWER: Hi Kristina,
I need to know exactly what is and isn't working now, what warning lights are 'on', what parts of the instrument cluster do and don't work. When you say "we just keep it running" does that mean it is driveable or if not, what is going on with the engine/transmission. How did you find a PCM so fast to get it replaced? Was this done at a dealership or an independent shop?
Roland
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QUESTION: Sorry about typo--meant to say we just can't keep it running for more than a few seconds.Engine 3.8L; No warning lights show, no codes; AC and air re-circulation/top two wiper lights flashing on dash board;engine light came on code said EGR valve needed to be replaced and was replaced twice check engine light now off this occurred around same time dash board lights were flashing don't know if it is related--probably not;then after EGR valve replace several months later the car shared shutting down; these lights were reset and when the car acted up again"shutting down" the flashing continued again;When car was shutting down abs and battery lights came on;Also for last six months battery inconsistently would need to be recharged for no apparent reason and was also replaced but same problem still continued;battery cells checked out ok; when I turn key to manually unlock driver's door a relay starts to flicker on very top of left hand side interior fuse box;when I turn the key off from ignition and pull out key occasionally just more recently the battery saver relay keeps clicking repeatedly; car was tested for draw by self and dealership showed no draw; dealership recommend pcm replace; we replaced by ourselves and they reprogrammed it successfully.
ANSWER: I wonder if when the dealer 'reprogrammed' the pcm they also took into account the vehicle theft security system? I assume you have that feature. The problem is when you set the alarm by locking the door with the key, the power door locks, or the key fob, and then come back to start the engine, if you don't successfully disarm the system, the way the engine controller protects against theft is to allow the engine to start but then it shuts it down (kills the spark/fuel pump/injectors) after about 2-3 seconds of operation. If the programming of the pcm was done today, and then you drove it home, and then you secured it, and then tried to start it and it shuts down in exactly the same amount of time, then you may indeed have an alarmed body computer which needs to be disarmed. Just a thought...In the meantime, please just experiment to see if the time between start and die is consistent/repeatable.
The relay that is clicking on the upper left is the door unlock relay, and it may be doing that if the battery voltage were a bit too low to activate it properly. I don't know what the 'battery saver' relay is, of which you speak. I will await your observations about whether the run time before shut down is variable or consistent. Once the 'no run' problem is resolved we can try to understand the balance of the current problem which I am still not clear about.
Roland
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QUESTION: After PCM installed and programed were able to drive the car for a few days and did not seem to have any problem with the security system;After PCM was installed we did use the key transmitter to lock and unlock the car without difficulty and the only time we used the key was when we had no power after the car shut down; I was wondering why would you think it is the alarm system when the vehicle has shut down one time in the beinging of the month and at the end of the month at night prior to pcm installed--Now shut downs occur within a few seconds after disconnecting the negative jumper from battery consistently; All the symptoms seem to be the same;I don't know if this useful but I did notice about 1year ago that my driver's outside mirror seemed to be stuck in a position trying to adjust itself in one direction while the car was off and it killed the battery: when I walk up to the vehicle I heard the mirror clicking and my battery was dead I recharged it and that never happened again.
AnswerHi Kristina,
It appears to me that either the battery is not accepting a charge (such that the voltage is too low to run all the systems), or that the alternator is not charging the battery (when you do have the engine running is the charging warning light on the dashboard illuminatated?) or that there is a short circuit that is dragging down the voltage of the system (but not blowing a fuse).
How old is the battery and how does that compare to the original warranty period?
Do you have a battery charger you can plug in to try charging the battery? You can get a trickle chrager for under $25 from an auto parts store.
Do you have a volt-ohm-amp meter that you could use to measure the voltage on the battery, and also to measure the current that is being drawn by the system when everything is turned off (which is called the 'ignition off draw)? You can get such a meter at an electronics store for less than $25.
Try removing fuse #28 (in the far rear of the box that is under the hood, and which is the 'ignition off draw fuse') while you are charging the battery overnight and then check the voltage on the battery and try to start the engine after replacing fuse 28.
If that solves the problem I would suspect that you have something that is drawing current from the battery all the time, like the mirror you mentioned, and that is preventing the battery from holding enough charge to keep the car going.
But you need to try this fuse removal/charge the battery approach to see if this is the case. Fuse 28 powers things like the mirrors/power door locks/radio present memory so don't be surprised to find those don't work when fuse 28 is out. Put the fuse back in and then try to start the car. It it runs then, we need to assess each of the devices that draws on fuse 28 to find out which one is the culprit.
I asked about the theft system because it too causes the engine to start and die in 2-3 seconds, which I thought might be what was happening.
Please understand that there is no magic answer I can pull from the air to solve the problem. It will take some testing/trying/measuring to solve this. It might be less confusing if you would use sentences with a period at the end of each, as sometimes I don't fully understand what you are writing.
I have asked you several questions and asked you to try several things so please do the best you can to do those.
Thanks,
Roland
